• Two infants developed evidence of antidiuretic hormone excess as a complication of infant botulism. Neither child received mechanical ventilatory support before the development of hyponatremia, serum hyposmolality, and urinary hyperosmolality. Both infants responded to fluid-intake restriction. The appearance of hyponatremla in an infant with botulism should suggest antidiuretic hormone excess. The recognition of this entity will lead to Its appropriate management with fluid-intake restriction.